Cutting and gouging torches and electrodes therefor



CUTTING AND GOUGING TORCHES AND ELECTRODES THEREFOR Fi led May 10, 1952 5 0 m y E a x w m w A Z v 4 E 4 %4 BY ry,

atent fiiice Patented June 19, 1956 CUTTING ANS GQUGENG TKERQHES AND ELECTRGDES THEREFGR Myron ill-avis Stepaih, Brenierton, Wash.

Appiication May .16, 52, Serial No. 287,145

9 Claims. {(Il. 2l)--15) This invention relates to electric are cutting and gouging apparatus and more particularly concerns an improved means for effectively utilizing the displacing force of a gas jet in conjunction with the heat of an electric are for cutting and gouging purposes. The invention is herein illustratively described by reference to the pre- 1 ferred form and application thereof, but it will be ap preciated that various modifications and changes therein may be made by those skilled in the art without departing from the underlying features involved as pointed out in the following specification and as set forth in the tap pended claims.

Cutting and gouging steel plates and the like at high rates of speed is permitted by the above mentioned basic method. In accordance therewith, the'electric arc is advanced progressively along the desired cutting or gouging line on the work and a high velocity screen of gas, such as air, directed against the molten metal behind the are effects its removal. However, if the gas jet orifice is located immediately adjacent the work itself so as to concentrate the full force of the issuing stream upon the hot spot, it obviously becomes necessary to reposition the orifice continuously relative to the electrode holder in order to compensate for the progressive consumption and shortening of the electrode with use. The task of thus holding and repositioning the gas jet orifice, if carried out manually, is tedious, inexact and in some instances may require the services of an additional skilled workman. On the other hand, automatic mechanism for progressively shifting the gas jet orifice relative to the electrode holder during the progress of a cutting operation tends to become complex, expensive, cumbersome and in some instances unsuitable because of its size or bulk.

For these reasons, it has been proposed to mount a gas jet orifice in fixed position on the electrode holder at or near the electrode gripped therein, with the jet stream directed along the length of the electrode toward the arc.- The difficulty with this arrangement, however, for some applications at least, is that the stream of gas necessarily diverges or spreads out with increasing distance from the orifice so that it is much less. forceful or effective witha long electrode than it is with a short or nearly consumed electrode, unless the gas pressure producing the stream is progressively reduced at a rate proportional to the rate of consumption or shortening of the electrode. Again the automatic or manual control of gas pressure tends to complicate matters and is something to avoid if possible.

in view of the foregoing considerations, a general object of the present invention is an improved cutting and gouging torch and electrode therefor utilizing to advantage the combined efiects of an electric arc and a gas pressure jet without encountering any of the above-mentioned difliculties of previous methods and apparatus. More specifically, it is an object to provide a cutting and gouging device of the fixed orifice type wherein the divergence of the jet stream is controlled or limited, at

2 least in the critical portions of the stream incident upon the work so that the effective force thereof in displacing the molten metal is not greatly different when the electrode is of original length or relatively long than it is when the electrode is largely consumed and considerably shorter in length.

A related object is a cutting and gouging torch and electrode combination wherein the electrode itself functions as a director or channelizer of gas issued from the jet orifice and yet the electrode is not subject to the manufacturing difficulties and other complications of tubular electrodes as heretofore proposed for special limited purposes. Moreover, the novel electrode is so formed as to be readily made in various thicknesses and lengths without altering its effectiveness for the above mentioned purpose as well as the usual purposes thereof. Such electrode is subject to a minimum amount of erosion due to the jet stream channelized thereby, imposes minimum resistance to flow of the gas therealong at high velocity and is adapted for manufacture by inexpensive rapidproduction methods such as extrusion processes and others.

A further object of the invention is an improved fixedorifice type electrode holder of simple, compact, durable and readily insulated or shielded form, relatively easy to manufacture and convenient to use.

Still another object of the invention is an improved electric arc cutting and gouging torch wherein the electrode is securely held in releasable manner in the electrode holder by novel clamp means having provision for automatically ejecting the electrode from its seat simultaneously with release thereof from a clamp arm. Thus in the event the electrode through the effects of heat tends to stick to a support in the holder and is too hot to be released by hand, the automatic ejecting element frees the electrode so that it will drop out of the holder quite readily.

Further specific objects include the, provision of a novel and improved gas valve control arrangement for gas jet type welding or cutting torches, and more particularly a control arrangement which does not require holding by the operator continuously throughout operation of the torch. The simple and compact mechanisms herein disclosed are self-detaining in either valve-open or valveclosed positions.

In brief terms, the improved cutting and gouging apparatus as herein illustratively described comprises a solid rod electrode of generally channeled form, i. e. having one side thereof troughed or grooved longitudinally for purposes mentioned above. The torch or holder cooperating with such electrode comprises'a supporting and locating longitudinal rib therein upon which the grooved side of the electrode is seated and held by a resiliently urged clamp arm. A second arm approximately perpendicular to the clamp arm is adapted to bear against the end face of the gripped electrode and swings thereagainst to eject the same from the holder simultaneously with swinging of the clamp arm away from the side of the electrode to release the same from its seat in the holder. A gas jet orifice fixed in the end of the holder close alongside the end edge of the locating rib seated in the electrode groove directs a high-velocity stream of gas in and along the length of said groove toward, the work. The electrode groove sides thereby serve as directing surfaces which channelize a portion of the jet stream at least so as to impinge the work with relatively undirninished force immediately adjacent the center of the arc whereat the temperature of the Work is the highest and the force of the jet stream is most effective to displace the metal.

These and other features, objects and advantages of the invention including various details of construction of the preferred form thereof will become more fully evident from the following description by reference to the accompanying drawings.

Figure 1 is a transverse sectional view of the improved cutting and gouging device taken on line 1-1 in Figure 2.

Figure 2 is a longitudinal sectional view of the device taken on an axial midplane thereof.

Figure 3 is a simplified perspective view illustrating the cooperative arrangement of the electrode and gas jet orifice in the novel electrode and holder combination.

Figure 4 is a simplified perspective view illustrating the operation of the improved cutting and gouging torch.

Figure 5 is a cross-sectional view of a modified form of electrode incorporating one feature of the invention.

Figure 6 is a fragmentary side view, partly in section, of a modified holder handle gas valve control combination.

Figure 7 is a transverse sectional view taken on line 7--7 in Figure 6.

Of suitable insulating material such as compressed fiber and a binder substance, the tubular handle 10 of the torch encases the electrode holder body or core piece 12 which is of steel, brass or other suitable metal. A spacer ring 14 secured inside the handle 10 near its butt end supports the body member 12 centrally therein. A frustoconical insulating sleeve 16, preferably of ceramic material, threaded upon and encircling the tip end of the core member 12, supports the adjacent end of the handle in concentric relationship therewith. The insulating shield 16 overlaps and bears against the inside rim and flange at the throat of a centrally apertured concave-convex hand guard 18 which seats in a groove in the tip or forward end of the handle 10.

Generally cylindrical in form, the metallic body or core piece 12 has a threaded socket in its base end which receives the threaded fitting 20 for connecting the concentric rubber conduit or hose 22 and internal electric cable 24 therewith as shown. A transverse bore of stepped diameter in the core piece near its base end forms the control valve cavity 26. Gas under pressure from the hose 22 is admitted into this cavity through longitudinal bores 28 in the fitting 20, and through a bore 30 extending between the inner end of the fitting bore, and the valve cavity 26. A longitudinal bore 32 in the core piece 12 extends between the tip end thereof and the enlarged portion of the valve cavity 26. The longitudinal bore 32 is located at or in the vicinity of the central longitudinal axis of the torch. A jet nozzle 34 threaded into the outer end of this bore in the core piece 12 directs a high-velocity stream of gas beyond the end thereof substantially parallel to the axis of the torch.

A gas control valve 36 installed in the valve cavity 26 comprises the poppet valve element 38 provided with a stem 40 which passes without contact through the apertured valve block 42 and slides for guidance through the apertured retaining plug 44 threaded into the outer end of the valve cavity. A valve return spring 46 seated between the base of the valve cavity and the head of the poppet valve 36 maintains the valve normally in closed position preventing passage of gas under pressure from the supply hose 22 to the discharge orifice or jet nozzle 34 Actuation of the poppet 'valve 38 toward open position is effected by means of the control member 48 comprising a wedge-shaped slider 50 bearing slidably on the inside wall of handle 10 under the end of valve stem 40. This slider has a lateral projection 52 thereon of reduced width which slides in a longitudinal guide slot 54 in the handle 10, and is retained in this slot by means of a keeper plate 56 secured thereto for sliding on the outside wall of the handle along the longitudinal edges of the slot. The keeper plate 56 functions as "a control button or knob by which the operator shifts the wedging block 50 between its valve-closed or retracted position nearest the butt end of the handle (right hand end in Figure 2) and its valve-opened or advanced position nearest the tip end of the handle. The end of the valve stem 40 which slides on the inclined surface of the slider 50 during forward movement of the latter is pressed into the valve cavity 26 to unseat the valve 38. Because of friction between the end of the stem 40 and the inner face of the slider the latter maintains its advanced position and holds the valve open until the slider 50 is manually retracted, so that the operator need not continuously hold open the valve during operation of the torch.

In Figures 6 and 7, the modified valve control arrangement accomplishes the same general result by a rotary movement instead of a longitudinal movement of a valve control element. In this latter form, the butt end of the tubular handle 10 rotatively supports a hollow cylindrical extension 58. An eccentric enlargement 60 of the otherwise centered bore 62 through the rotary extension piece 58 provides a wedging cam surface upon which the end of the valve stem 44} slides for valve actuation and deactuation as the member 58 is rotated back and forth relative to the handle, hence to the core piece 12. Retaining screws 64 threaded through opposite sides of the butt end of the handle 10 enter circumferential grooves 66 in the overlapping flange of rotary member 58 which slides rotatably around inside the end of the handle. The rotational limits of the member 53 relative to the handle are established by contact between the ends of the slots and the respective screws 64. These slots are circumferentially located in relation to the eccentricity of cam surface 60 such that in one limit position the valve 38 will be fully open and in the opposite limit position the valve will be fully closed.

The tip end of the core piece 12 is provided with an electrode receptacle opening 68 adjacent the bore 32, which opening continues into a complemental receptacle groove 70 formed in one side of the core piece. Extending lengthwise along the base of the groove 70 and the contiguous side of the opening 68 there is formed a convexly shaped projection or rib 72. In the illustrated case (Figure 1) this electrode locating and supporting rib is formed cross-sectionally as the minor segment of a cylindrical surface although equivalent forms of a specifically different nature may be substituted therefor.

The longitudinal gas duct 32 extends through, or closely adjacent and along this rib, so that the discharge nozzle 34 is positioned close alongside and directed substantially parallel to the line of the crest of the rib.

The solid rod electrode 74 of carbon or a suitable metal has a longitudinal groove 76 therein which groove conforms to or is adapted to seat upon the convex rib 72. Thus when the end of the electrode 74 is inserted into the receptacle formed by the opening 68 and groove 70, the grooved side of the electrode receives and seats upon the rib 72 and the electrode is thereby so located and rotatively positioned in the holder that the discharge stream from the jet nozzle 34 is directed in and along the electrode groove 76 (Figure 3).

The electrode clamp device comprises the multiple-arm lever 78 pivoted on the transverse pin 80 extending between opposite sides of the groove 70. This clamp device serves the dual purpose of pressing the holder-inserted end of the electrode firmly down against the ribbed base of the groove 70 and of ejecting the electrode stub from the holder simultaneously with subsequent release of the electrode from hold-down pressure. The lever 78 comprises the electrode clamp or hold-down arm 78a engageable with the side of the electrode, the ejecting arm 78b ap proximately perpendicular thereto engageable with the end of the electrode, and the actuating or control arm 78c extending rearwardly from the pivot 80 in general alignment with the clamp arm 78a along the space defined between the side of the handle 10 and the adjacent grooved side of the core piece 12. A spring 82 seated in a side bore 84 in the core piece presses the end of the actuating Mm 780 outward and thereby establishes normal clamping pressure of the clamp arm 78a against the side of the electrode. An actuating button 86 mounted on the end of the actuating lever normally projects outwardly through an opening 88 in the side of the handle 10. By pressing on this button the clamp arm is raised from the electrode against the force of spring 82 and simultaneously therewith the electrode-ejecting arm 78b is swung against the end of the electrode. The electrode is at once released from arm 78a and pressed outwardly of the receptacle opening 68 by arm 78b upon actuation of the single control button 86. The purpose of lever 78b is not necessarily to eject the electrode completely from the holder but at least to initiate such movement so as to free it from the rib 72 in case it tends to become stuck thereon due to the effects of heat and cannot be freed by hand due to its lingering high temperature.

Bleeder openings 90 and 92 in the base of the groove 70 and the base of the spring socket 84, respectively, permit escape of gas under pressure from the duct 32 for cooling the clamp device 78 and the return spring 82 during operation of the torch.

In operation the gas control actuator 56 is initially in its retracted position (its right hand limit position in Figure 2) corresponding to the seated or closed position of the poppet valve 38. With the electrode clamp control button 86 depressed, and the arm 78a thereby raised, an electrode is slid endwise into the holder through the receptacle opening 68 until its end abuts the arm 78b. The grooved side of the electrode is sealed upon the conformed locating rib 72 so that the groove is necessarily located adjacent to the discharge orifice 34. The button 86 is then released to permit. the arm 78a to be swung down and the arm 78]) to be swung back under recoil force of the spring 82, so that the electrode may he slid the final remaining distance into the holder and be clamped therein under pressure applied by the spring. As shown in Figure 4, an electric arc may then be struck between the edge of the work and the tip of the electrode with the electrode holder oriented with respect to the work so that the grooved side of the electrode faces to the rear or away from the intended direction of progressive cutting movement (arrow in Figure 4). The gas control valve 38 is then or previously opened by sliding of the gas control button 56 to its leftmost position in Figure 2.

The high velocity stream of gas emerging from the jet nozzle 34 and directed along the elctrode between the sides of the groove therein impinges upon the most intensely heated area of the work--namely the area near and immediately behind the center of the arc. Its force, at least in this critical area, is preserved by the channelizing influence of the electrode groove sides such that the molten metal is then displaced from the work with the desired effect behind the advancing are as previously described. Thus the effective force of the jet stream is not greatly less in the critical area behind the are with a long electrode than it is with a nearly consumed or relatively short electrode.

The provision of a grooved or channel-shaped electrode preferably of uniform cross section throughout its length is uniquely applicable to the problem of cutting and gouging with electric arc apparatus. Electrodes of this form may be manufactured by extrusion methods or other equally inexpensive and simple processes, may vary considerably in size cross-sectionally as Well as in length without altering the operation thereof nor requiring different holders as long as the depth and width of the electrode groove are approximately the same, depending upon the particular clamping arrangement; moreover, the use of a grooved or open-sided conduit in the electrode as distinguished from a bore through a tubular electrode subjects the body of the electrode to gas stream erosion in a lesser degree and sets up less resistance to flow of the high-velocity stream or the critical portion thereof, than in the case of a tubular electrode. At the same time the force of the jet-stream is felt at or near the center of the are as desired.

A modified form of electrode 76'- appears in Figure 5 wherein the electrode is of more nearly true channelshaped form. It will be appreciated, however, that a variety of grooved or different channel-shaped electrode forms may be utilized for purposes of the invention and will be effective when employed in an electrode holder wherein a force jet of gas is emitted in and along the length of the electrode groove or channel for achieving the desired cutting or gouging action.

I claim as my invention:

1. Electric arc apparatus comprising an electrode in the form of an elongated conductive rod having on one side thereof means forming an open-sided gas channel extending throughout the length of said rod, and electrode holder means comprising an electrode supporting member providiug a seat for the channeled side of said electrode rod, a clamp member pressing upon the opposite side of said electrode rod and urging it to its seat, and gas jet orifice means in the end of said holder means immediately adjacent said electrode rod seat hence adjacent the channeled side of said electrode rod, said gas jet orifice means being disposed for directing a high velocity stream of gas in and along said gas channel toward the end of said electrode rod projecting from the holder.

2. Apparatus as defined in claim 1, wherein the electrode supporting member of the holder comprises a loeating projection formed to enter the channeled side of the electrode rod and extend longitudinally thereof, and the gas jet orifice means comprises a single aperture lo,- cated in the end of the holder adjacent to said projection.

3. Electric are cutting and gouging apparatus comprising an electrode in the form of an elongated conductive rod having on one side thereof means defining an open sided gas conduit extending longitudinally substantially throughout the length of said rod, and electrode holder means having in fixed position thereon gas jet orifice means directed substantially in and along the length of said gas conduit of the electrode held in said holder.

4'. Electric are cutting and gouging apparatus comprising an electrode in the form of an elongated conductive rod having on one side thereof means defining an opensided gas conduit extending longitudinally substantially throughout the length of said rod, and electrode holder means having in fixed position thereon gas jet orifice means directed substantially in and along the length of said gas conduit of the electrode held in said holder, said electrode holder means further comprising a core piece having a longitudinal gas conduit bore therein terminating in the gas jet orifice, and having an end-opening electrode receptacle located in the end thereof immediately adjacent said orifice, the longitudinal interior side of said receptacle nearest the orifice having an electrode locating projection thereon entering the rods gas conduit for positioning the open side thereof to face the jet stream issuing from the orifice.

5. An electric are cutting and gouging torch adapted to hold an electrode in the form of an elongated conduc tive rod, comprising electrode holder means having in fixed position thereon gas jet orifice means directed substantially parallel to the length of said electrode held in said holder, said holder means including a handle of generally cylindrical form exteriorly, extending substantially in alignment with the electrode held in said holder, 21 core piece encased by said handle, having a longitudinal gas conduit bore therein terminating in the gas jet orifice, and having an end-opening electrode receptacle located in the end thereof immediately adjacent said orifice, the longitudinal interior side of said receptacle nearest the orifice comprising an electrode supporting face, said core piece having a side slot therein opening laterally from said receptacle in the side thereof opposite said supporting face, and an electrode clamp device including a clamp arm received in said slot extending generally lengthwise of the holder, hence generally parallel to the side of an electrode contacted therebyresting against said supporting face, means on said core piece pivotally supporting said clamp arm to permit swinging of said clamp arm about an axis transverse to the holder into and out of clamping engagement thereof with the side of such electrode, an actuating arm extending generally lengthwise of the holder from said pivot means in the direction opposite from said clamp arm, said clamp arm being arranged for manual operation to effect swinging of said clamp arm into and out of contact with the electrode, spring means urging such clamp arm into clamping engagement with the electrode rod, and an electrode ejecting arm projecting generally at right angles from said clamp arm at a location in the vicinity of said pivot means, said ejecting arm projecting laterally into said electrode receptacle in the core and across the end of an electrode received in said receptacle for pressing endwise against the end of such electrode to force the same out of the holder receptacle accompanying release of such electrode by swinging movement of the clamp arm manually against the force of said spring means.

6. An electric arc, gas jet type cutting and gouging torch adapted to hold an electrode rod therein of channelform, said torch comprising electrode gripping means having opposing gripping faces one of which is adapted peculiarly to seat against the channeled or concave side of such an electrode and the other of which is adapted peculiarly to seat against the opposite or convex side of such electrode, and gas jet orifice means carried by said electrode gripping means immediately adjacent said first-mentioned gripping face, said orifice being directed longitudinally of an electrode gripped in the torch, whereby the issuing jet stream flows along the electrode rod channel.

7. The torch defined in claim 6, wherein the firstmentioned gripping face has a transversely convex arcuate form.

8. An electric arc, gas jet type cutting and gouging torch adapted to hold an electrode rod therein having two opposite sides, at least one of which is channeled lengthwise of said rod throughout substantially the full length thereof, said torch comprising electrode gripping means having opposite gripping faces, one of which is 8 adapted peculiarly to seat against a particular one of said two-sides of such electrode rod and the other of which is adapted to seat against the opposite of said two sides, and gas jet orifice means mounted on said torch in fixed position relative to the gripping face adapted to seat against the channeled side of the electrode rod, said gas jet orifice means being directed longitudinally of the groove in the electrode rod gripped in the torch, whereby the issuing jet stream flows along and is partially guided by such side channel to the projecting end of the electrode rod at which the electric arc is struck.

9. The torch defined in claim 8, wherein the gripping means face which is peculiarly adapted to seat against a particular one of the two sides of the electrode rod has a protuberant portion adapted to enter the electrode rod channel, and wherein the gas jet means is formed as an orifice in the end of said protuberant portion facing along the projecting length of the electrode rod gripped in the torch, said gas jet orifice having an axis which is substantially aligned with the electrode gas guiding channel.

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